Photographic silver halide materials supersensitized with a combination of a triazole and a cyanine dye

ABSTRACT

PHOTOGRAPHIC SILVER HALIDE EMULSIONS ARE SUPERSENSITIZED WITH THE COMBINATION OF A PHOTOGRAPHIC SPECTRAL SENSITIZING METHINE DYE AND A HETEROCYCLIC COMPOUND SELECTED FROM A PYRAZOLE, A 5-PYRAZOLONE, A 3-PYRAZOLONE, A 3,5-PYRAZOLIDINEDIONE, A TRIAZOLE, A TETRAZZOLE, A XANTHINE, AN IMIDAZOLE, AN IMIDAZOLIDINE AND AN AMIDAZOLINIUM SALT.

United States Patent Oihce 3,592,656 Patented July 13, 1971 Int. Cl.G03c 1/28 US. Cl. 96--126 6 Claims ABSTRACT OF THE DISCLOSUREPhotographic silver halide emulsions are supersensitized with thecombination of a photographic spectral sensitizing methine dye and aheterocyclic compound selected from a pyrazole, a S-pyrazolone, a3-pyrazolone, a 3,5-pyrazolidinedione, a triazole, a tetrazole, axanthine, an imidazole, an imidazolidine and an imidazolinium salt.

This invention relates to novel photographic silver halide emulsionscontaining a new supersensitizing combination.

It is well known in the photographic art that certain cyanine dyesextend the spectral sensitivity of photographic emulsions. It is furtherknown that a number of such dyes in combination with each other .or withcertain other compounds markedly alter the sensitivity of photographicemulsions, for example in relative speed, compared with the individualdyes by themselves in such emulsions. While supersensitizingcombinations of the above kind have been proposed for variousphotographic uses, only a relatively few have proven entirelysatisfactory for commercial photographic applications. Consequentlythere is still need in the art for improved supersensitizingcombinations comprising methine cyanine dyes.

It is, accordingly an object of this invention to provide a new class ofsupersensitizing combinations for photographic silver halide emulsions.

Another object of this invention is to provide novel emulsionscontaining novel supersensitizing combinations, and photographicelements prepared therewith.

Other objects of the invention will be apparent from this disclosure andthe appended claims.

I have now made the important discovery that new and improvedsupersensitizing combinations for lightsensitive photographic silverhalide emulsions are produced with (l) a heterocyclic compound selectedfrom a pyrazole, a S-pyrazolone, a 3-pyrazolone, a3,5-pyrazolidinedione, a triazole, a tetrazole, a Xanthine, animidazole, an imidazolidine and an imidazolinium salt; and, (2) aphotographic spectral sensitizing methine dye.

Especially good results are obtained in accordance with this inventionwhen the heterocyclic compound is a pyrazolone; a l,2,3,4-tetrazole; a1,2,4-triazole; an imidazole; or, an imidazolinium salt. Someparticularly useful (III) N wherein A represents the atoms required tocomplete an imidazole nucleus, such as imidazole or benzimidazole; Rrepresents a hydrogen atom, an alkyl group of from 1 to 4 carbon atoms,such as methyl, 2-carboxypropyl, butyl, etc., or an aryl group such asphenyl; R represents an aryl group, such as phenyl or2,4,6-trichlorophenyl; R represents an aryl group such as phenyl, or anamino group such as an arylamino group, e.g., 3,4-dichloroani1ino,anilino, 4-methylsulfonamidophenylamino, or an amido group such as3,5-disulfobenzamido; R represents a hydrogen atom or an arylthio groupsuch as 3-octadecyclarbamylphenylthio; R represents a hydrogen atom oran aryl group such as phenyl; R represents an aryl group such as phenyl,4 cyanophenyl, 4 methoxyphenyl, 4 carboxyphenyl, naphthyl, a benzoylgroup, or pyridyl (EV-pyridyl or 4'- pyridyl); R and R each represents ahydrogen atom, or an aryl group such as phenyl; and, R represents ahydrogen atom or an amino group.

Typical heterocyclic compounds which can be used in this inventioninclude those listed in the following Table 1.

phenyD-S-pyrazolone. 3-(3,4-dichloroanilino)-1-(2,4,-trichlorophenyl)-5- pyrazolone.

VIII bis[5m%thyl-2-p-sulfophenyl-3-pyrazolone-(4)1-meth1ne oxono IX3-(3,5-dicarbeth0xybenzamido)-4(3-oetadecylearbamylphenylthio)-1-phony1-5-pyrazolone.X 1,2-d1pl enyl-3,S-pyrazolidinedione. XI. p-(3,5-d1phenyl-2-pyrazolinl-yl)benzaldehyde. XII. 5-benzyl-5phenyl-4-phenylazopyrazole. XIII.1,5-diphenyltetrazole. XIV 1,3-diphenyl-5-hydroxy-pseudo-tetrazole. $6 5N HO-(l3 N-H 1L N C 5H5 XV 5-(3,4-d.imethoxyphenyl)tetrazole. XVII-5-(4-cyanophenyl) tetraZOle-HzO XIX- 5-(4-earboxyphenyl) tetrazole- H2OXX. 5-pheny1tetrazole.

5-benzoyltetraz0le.

XXVIA 4-(N-methyl-p-toluenesulfonamido)-l-(1-phenyl-5tetrazolyloxy)-2methylthi0benzene.

XXVII 3-amino-5-phenyl-l,2,4-trizaole.

1,5-diphenyl-1,2,4-triazole. 4amino-3,5-di(p-aminophenyl)-l,2,4trlazolo.

XXXI. Poly(l,2,4triazole). XXXII.4-(5-cyanomethyl-1-phenyl-l,2,4-triazol-3-yl)-benzaldehyde-Nchlorophenylhydrazone. XXXIIL 3,3tp-pllienylenebis(fi-cyanomethyl-1-pheny1-1 2,4-

nazo XXXIV 4-phenylimidazole. XXXV 2-(4,S-diphenyl-Z-imidazolyl)phenol.XXXVI 1,3-diphenylimidazolidine. XXXVIL. l,3-diphenylimidazoliniumperchlorate. XXXVIII 2(3-pyridyl)benzimidazole. XXXIX.2-(4pyridyl)benzimidazole. XL. B-(Z-mercaptobeuzimidaz0le)propionieacid. XLI 3-isopentyl-2,6-dithioxanthine.

The above classes of heterocyclic compounds are well known and methodsfor their preparations are described in the various prior art patentreferences and literature. Some of the references relating to a numberof the specific compounds mentioned in above Table 1 are included hereinfor illustrative purposes, for example, reference can be had to ChemicalAbstracts 22, P3170 25, P3364 32, 5831 41, P1699e; 45, P7603 c; 47,4335c; 49, 9153c: 51, 13876i; 53, 2216c; 53, 4317d; 54, 14234e; 55,1644c; 55, 2626c; 55, 16520c; 62, P177821; etc.

The rnethine dye spectral sensitizers of the invention are representedby the following formulas:

wherein e and 12 represent a positive integer of from 1 to 2; d and Ineach represents a positive integer of from 1 to 3; L represents arnethine linkage, e.g. =CH,

etc.; R and R each represents an alkyl group, including substituted:alkyl (preferably a lower alkyl containing from 1 to 4 carbon atoms),e.g., methyl, ethyl, propyl, isopropyl, butyl, hexyl, cyclohexyl, decyl,dodecyl, etc., and substituted alkyl groups (preferably a substitutedlower alkyl containing from 1 to 4 carbon atoms), such as a hydroxyalkylgroup, e.g., fi-hydroxyethyl, w-hydroxybutyl, etc., an alkoxyalkylgroup, e.g., B-methoxyethyl, w-blltoxybutyl, etc., a carboxyalkyl group,e.g., B-carboxyethyl, w-carboxybutyl, etc.; a sulfoalkyl group, e.g.,fl-sulfoethyl, w-sulfobutyl, etc., a sulfatoalkyl group, e.g.,fi-sulfatoethyl, w.-sulfatobuyl, etc., an acyloxyalkyl group, e.g., [3-acetoxyethyl, 'y-acetoxypropyl, w-butyryloxybutyl, etc., analkoxycarbonylalkyl group, e.g., fl-methoxycarbonylethyl,w-ethoxycarbonylbutyl, etc., or an aralkyl group, e.g., benzyl,phenethyl, etc., or, any aryl group, e.g., phenyl, tolyl, naphthyl,methoxyphenyl, chlorophenyl, etc.; X represents an acid anion, e.g.,chloride, bromide, iodide, thiocyanate, sulfamate, perchlorate,p-toluenesulfonate, methylsulfate, etc.; R represents a hydrogen atom,an alkyl group of 1-4 carbon atoms, including substituted alkyl, e.g.,methyl, ethyl, isopropyl, butyl, dimethylaminopropyl, benzyl, phenethyl,etc. or an aryl group, e.g., phenyl, tolyl, chlorophenyl, methoxyphenyl,naphthyl, etc.; D represents an atom of oxygen or sulfur; or thenon-metallic atoms necessary to complete a diazole ring, e.g., D is NRwherein R is an alkyl group of 1 to 4 carbon atoms, e.g., methyl, ethyl,isopropyl, butyl, etc., or an aryl group such as phenyl, tolyl,chlorophenyl, rnethoxyphenyl, naphthyl, etc.; Z and Z each representsthe non-metallic atoms necessary to complete the same or different 5- to6-membered heterocyclic nucleus such as used in cyanine dyes which maycontain a second hetero atom such as oxygen, sulfur, selenium ornitrogen, such as the following nuclei:

a thiazole nucleus, e.g., thiazole, 4-methylthiazole, 4- phenylthiazole,S-methylthiazole, S-phenylthiazole, 4,5- dimethylthiazole,4,5-diphenylthiazole, 4-(2-thienyl) thiazole, benzothiazole,4-chlorobenzothiazole, S-chlorobenzothiazole, 6-chlorobenzothiazole,7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole,6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 5phenylbenzothiazole, 4 methoxybenzothiazole, S-methoxybenzothiazole,6-methoxybenzothiazole, 5-i0dobenzothiazole, 6 iodobenzothiazole, 4-

ethoxybenzothiazole, S-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6dimethoxybenzothiazole, 5,6 dioxymethylenebenzothiazole,S-hydroxybenzothiazole, 6 hydroxybenzothiazole, naphtho[2,1 d]thiazole,naphtho- [l,2-d]thiazole, 5 methoxynaphtho[2,3 d]thiazole, 5-

ethoxynaphtho[2,3-d1thiazo1e, 8 methoxynaphtho[2,3-d]

thiazole, 7-methoxynaphtho[2,3-d]thiazole, 4methoxythianaphtheno-7,6'-4,5-thiazole, etc.;

an oxazole nucleus, e.g., 4 methyloxazole, 5 methyloxazole,4-phenyloxazole, 4,5-diphenyloxazole, 4-ethy1- oxazole,4,5-dimethyloxazole, S-phenyloxazole, benzoxazole, S-chlorobenzoxazole,S-methylbenzoxazole, 5- phenylbenzoxazole, 6-methylbenzoxazole,5,6-dimethylbenzoxazole, 4,6 dimethylbenzoxazole, 5 methoxybenzoxazole,5 ethoxybenzoxazole, 5-chlor0benzoxazole, 6-methoxybenzoxazole,S-hydroxybenzoxazole, 6- hydroxybenzoxazole, naphtho [2,1-d]oxazole,naphtho- [l,2-d]-oxazole, etc.;

a selenazole nucleus, e.g., 4-methylselenazole, 4-phenylselenazole,benzoselenazole, 5-chlorobenzoselenazole, 5-me'thoxybenzoselenazole,S-hydroxybenzoselenazole, tetrahydrobenzoselenazole,naphtho[2,1-d]selenazole, naphtho[1,2-d]se1enazole, etc.;

a thiazoline nucleus, e.g., thiazoline, 4-methylthiazoline,

etc.;

a pyridine nucleus, e.g., 2-pyridine, S-methyI-Z-pyridine,

4-pyridine, 3-methyl-4-pyridine, etc.;

a quinoline nucleus, e.g., 2-quinoline, 3-methyl-2-quinoline,S-ethyI-Z-quinoline, 6-chloro-2-quinoline, 8-chloro- Z-quinoline,6-methoxy-2-quinoline, 8-ethoxy-2-quinoline, 8-hydroxy-2-quinoline,4-quinoline, 6-rnethoxy-4- quinoline, 7-methyl-4-quinoline,8-chloro-4-quinoline, 1- isoquinoline, 3,4-dihydro-l-isoquinoline,3-isoquino1ine, etc.;

a 3,3 dialkylindolenine nucleus, e.g., 3,3 dimethylindolenine,3,3,5-trimethylindolenine, etc.; and,

an imidazole nucleus, e.g., imidazole, l-alkylimidazole, l-

alkyl-4-phenylimidazole, 1-alky1-4,5-dimethylimidazole, benzimidazole, 1alkylbenzimidazole, 1 aryl-5,6-dichlorobenzimidazole, l-alkyl-lH-naphth[1,2-d] imidazole, 1-aryl-3H-naphth[ 1,2-d1imidazole,l-alkyl-S-methoxy-1H-naphtha[1,2-d]imidazole, etc.;

and QQ represents the non-metallic atoms necessary to complete a 5- or6-membered heterocyclic ketomethylene nucleus of the type used inmerocyanine dyes typically containing a hetero atom selected fromnitrogen, sulfur, selenium, and oxygen, such as a 2-pyrazolin-5-onenucleus, e.g., 3-methyl-1-phenyl-2- pyrazolin-S-one,1-phenyl-2-pyrazolin-5-one,1-(2-benzothiazolyl)3-methyl-2-pyrazolin-5-one, etc.;

an isoxazolone nucleus, e.g,, 3-phenyl-5(4H)-is oxazolone,

3-methyl-5 (4H)-isoxazolone, etc.;

an oxindole nucleus, e.g., 1-alky1-2-oxindoles, etc.;

a 2,4,6-triketohexahydropyrimidine nucleus, e.g., barbituric acid or2-thiobarbituric acid as well as their 1- alkyl (e.g., l-methyl,l-ethyl, l-propyl, l-heptyl, etc.) or 1,3-dialkyl (e.g., 1,3-dimethyl,1,3-diethyl, 1,3-dipropyl, l,3-diisopropyl, 1,3dicyclohexyl,1,3-di(fl-me thoxyethyl), etc.; or 1,3-diaryl (e.g., 1,3-diphenyl, 1,3-di(p-chlorophenyl) 1,3 di(p-ethoxycarbonylphenyl), etc.); or l-aryl(e.g., 1- phenyl, l-p-chlorophenyl, 1-pethoxycarbonylphenyl), etc.) or1-alkyI-3-aryl (e.g., 1- ethyl-3-phenyl, 1-n-heptyl-3-phenyl, etc.)derivatives;

a rhodanine nucleus (i.e., 2-thio-2,4-thiazolidinedione series), such asrhodanine, 3-alkylrhodanines, e.g., 3-ethylrhodanine, 3 allylrhodanine,etc., 3 carboxyalkylrhodanines, e.g., 3-(2-carboxyethyl)rhodanine, 3-(4-carboxybutyl)rhodanine, etc., 3 sulfoalkylrhodanines, e.g., 3 (2sulfoethyl)rhodanine, 3-(3-sulfopropyl)- rhodanine,3-(4-sulfobutyl)rhodanine, etc., or 3-arylrhodanines, e.g.,3-phenylrhodanine, etc.;

a 5,7 dioxo-6,7-dihydro-5-thiazolo[3,2-a] pyrimidine nucleus, e.g., 5,7dioxo-3-phenyl-6,7-dihydro-S-thiazolo- [3,2-a]pyrimidine, etc.;

' a 2-thio 2,4-oxazolidinedione nucleus (i.e., those of the2-thio-2,4(3H,5H)-oxazoledione series) e.g., 3-ethyl-2- thio-2,4oxazolidinedione, 3-(2-sulfoethyl)-2-thio-2,4- oxazolidinedione, 3-(4sulfobutyl) 2-thio-2,4-oxazolidinedione, 3-(3-carboxypropyl)-2-thio-2,4oxazo1idinedione, etc.;

a thianaphthenone nucleus, e.g., 3-(2H)-thianaphthenone,

etc.;

a 2-thio-2,S-thiazolidinedione nucleus (i.e., the 2-thio-2,5--(3H,4H)-thiazoledione series), e.g., 3-ethyl-2-thio-2,5-thiazolidinedione, etc.;

a 2,4-thiazolidinedione nucleus, e.g., 2,4-thiazolidinedione,3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidine dione,3-u-naphthyl-2,4-thiazolidinedione, etc.;

a thiazolidinone nucleus, e.g., 4-thiazolidinone, 3-ethyl-4-thiazolidinone, 3-phenyl-4-thiazolidinone, 3-u-naphthyl-4-thiazolidinone, etc.;

2-thiazolin-4-one nucleus, e.g., 2 ethylmercapto-Z- thiazolin-4-one,2-alkylphenylamino-2-thiazolin-4-one,

2-diphenylamino2-thiazolin-4-one, etc.;

a 2-imino-4-oxazolidinone (i.e., pseudohydantoin) nucleus;

a 2,4-imidazolidinedione (hydantoin) nucleus, e.g., 2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, 3-phenyl-2,4-imidazolidinedione, 3-or-naphthyl-2,4-imidazolidinedione, 1,3diethyl-2,4-imidazolidinedione, 1- ethyl-3-phenyl 2,4imidazolidinedione, 1-ethy1-3-anaphthyl 2,4 imidazolidinedione,1,3-diphenyl-2,4- imida zolidinedione, etc.;

a Z-thio-2,4-imidazolidinedione (i.e., 2 thiohydantoin) nucleus, e.g.,2-thio-2,4-imidazolidinedione, 3-ethyl-2- thio-2,4-imidazolidinedione, 3(4-sulfobutyl)-2-thio- 2,4 imidazolidinedione, 3 (2-carboXyethyl)-2thio-2,4-imidazolidinedione, 3 phenyl-2-thio-2,4-imidazolidinedione,3-u-naphthyl-2-thio-2,4-imidazolidinedione,1-ethyl-3-phenyl-2-thi0-2,4-imidazolidinedione, l-ethyl-3-a-naphthyl-Z-thiO-Z,4-imidazolidinedione,1,3-diphenyl-2-thio-2,4-imidazolidinedione, etc.;

a Z-imidazolin-S-one nucleus, e.g., 2-propylmercapto-2- imidazolinS-one,etc.

Typical cyanine spectral sensitizing dyes of the invention representedby Formulas IV, V and VI above include those listed in the followingtable.

benzothiazolylideney methylene]-6-methyl-4H- pyran.

L 1,1-diethyl-2,2-oyanine iodide. M 3,3-diethyloxacarbocyanine iodide. N1,3-diethylthia-4-carbocyanine iodide.

1,3-diethyloxai carbooyanine iodide.

3 3'-di- 3-hydroxyethy]thiadicarbocyanine iodide.

3 3-di-flhydroxyethylthiadicarbocyanine bromide.

-diethy1oxatricarbocyanine iodide.

3-diethyl-4,5,4,5-naphthothiadicarbocyanine iodide.

3,3-dimethyl-8,12-diphenoxyoxadicarbocyanine iodide.

10-oyano-3,3'-diethy1o radiearbocyanine iodide.

, -tetraphenylthiazolodicarbocyanine iodide.

anine hydroxide.

W Anhydro-3-ethyl-5-phenyl-1-(4-sulfobutyl)thia-4-carbocyaninehydroxide. X 3,3'-diethylthiadicarbocyanine iodide.

. 5-[di-(1-ethyl-2(1H)-B-naphthothiazolylidene)isopropylidenel-1,3-di(fl-methoxyethyl)-barbitu ric acid.

Z 2[(Z-benzothiazolylethoperchlorate)rnethylene1-3-(B-dimethylaminopropyl)-5-[(l-methylnaphtho[1,2-d]thiazolin-2-ylidene)-l-phenylethylidene]-4thiazolidinone.

The methine dyes of the invention illustrated by those listed in aboveTable 2 have been previously described in the literature and methods fortheir preparations are well known. Included among the more pertinentreferences are the following.

Zeh et al. U.S. Pat. No. 2,068,047 issued 1/ 19/37 Koslowsky U.S. Pat.No. 2,107,379 issued 2/8/38 Mees U.S. Pat No 2,158,883 issued 5/16/39Carroll et al. U.S. Pat. No. 2,177,635 issued 10/3/39 Brooker et al.U.S. Pat. No. 2,213,238 issued 9/3/40 Brooker U.S. Pat. No. 2,307,916,issued 1/12/43 Brooker et al. U.S. Pat. No. 2,313,922, issued 3/16/43Schneider U.S. Pat. No. 2,374,505 issued 4/24/45 Falleson et al. U.S.Pat. No. 2,378,917 issued 6/26/45 Brooker U.S. Pat. No. 2,454,629 issued11/23/48 Thompson U.S. Pat. No. 2,535,993 issued 12/26/50 Carroll et a1.U .S. Pat. No. 2,950,196 issued 8/23/60 Jones U.S. Pat. No. 2,961,318issued 11/22/60 Tabor et al. U.S. Pat. No. 3,335,010 issued 8/8/67Brooker et al. U.S. Patent Reissue No. 24,292, Reissued 3/ 19/57 BritishPat. No. 435,235 accepted 8/ 28/ 35 Dye K can be prepared by heatingcompounds having the following formulas:

in triethylamine and ethanol, to obtain an intermediate of the formula:

02115 The above intermediate is then reacted with a compound of theformula:

6 CHa by heating in pyridine and triethylamine, to obtain dye K.

According to the invention, one or more of the heterocyclic compoundsrepresented by Formulas I, II, III or IIIa above are incorporated withone or more of the cyanine dyes represented by Formulas IV, V and VIabove. The invention is particularly directed to gelatinosilver-halidedeveloping-out emulsions. However, the supersensitizing combinations canalso be employed in silver halide emulsions in which the carrier ofvehicle is a hydrophilic colloid other than gelatin, such as, forexample, albumin, agar-agar, .gum arabic, alginic acid, etc., or ahydrophilic resin such as polyvinyl alcohol, polyvinyl pyrrolidone, acellulose ether, a partially hydrolyzed cellulose acetate, acrylamidepolymers, etc., which has no deleterious efiect upon the light sensitivesilver halide. The heterocyclic compounds of Formulas I, II, III andIIIa and the dyes of Formulas IV, V and VI, can be employed in thecombinations of the invention in various concen trations depending uponthe particular emulsion, concentration of the silver halide, particularresults desired, etc. The optimum concentration of an individualsensitizing dye can be determined in a manner well known to thoseskilled in the art by measuring the sensitivity of a series of testportions of the same emulsion, each portion containing a differentconcentration of the sensitizing dye. In general, the heterocycliccompounds in my invention have little or no sensitizing action bythemselves alone in the emulsions employed. Ordinarily, the optimum ornear optimum concentration of the cyanine dyes herein is of the order001 to 1.2 g. per mole of silver halide in the emulsion, and that of theheterocyclic compound herein is of the order of from about 0.02 to 5.0g., but generally in the range of about 0.3 to 1.0 g., per mole ofsilver halide. The preferred combinations range about from 10 to 50% byweight of the cyanine dye and conversely about from 90 to 50% by weightof the heterocyclic compound.

The methods of incorporating sensitizing dyes in silver halide emulsionsare well known to those skilled in the art and these known techniquesare employed in dispersing the dyes of the invention in the emulsions.In practicing my invention the sensitizing dyes and the heterocycliccompounds can be directly dispersed in the emulsions, or they can firstbe dissolved in some convenient solvent, such as pyridine, methylalcohol, acetone, etc. (or mixtures of such solvents), or diluted withwater in some instances, and added to the emulsions in the form of thesesolutions. If desired, the components can be separately dissolved in agiven solvent and added separately to the emulsion, or they can bedissolved in the same or different solvent and these solutions mixedtogether before addition is made to the silver halide emulsions. Thedyes and heterocyclic compounds of the invention are dispersed in thefinished emulsions in such manner as to be uniformly distributedthroughout the emulsions prior to coating on a suitable support, such aspaper, glass, cellulose ester film, polyvinyl resin film (e.g.,polystyrene film, polyvinyl chloride film. etc.), polyester film, etc.The following procedure has been found quite satisfactory: Stocksolutions of the dyes and heterocyclic compounds of Formulas I, II, IIIand IIIa and the dyes of Formulas IV, V and VI above are prepared byseparately dissolving these in appropriate solvents as described above.Then, to the flowable silver halide emulsion, the desired amount ofstock solution of one of the dyes is slowly added while stirring theemulsion. Stirring is continued until the dye is thoroughly incorporatedin the emulsion. Then, the desired amount of stock solution of one ofthe heterocyclic compounds is slowly added to the emulsion whilestirring. Stirring is continued until the added materials areincorporated in the emulsion. The supersensitized emulsions can then becoated on a suitable support and the coating allowed to dry. In someinstances, it may be desirable to heat the supersensitized emulsion fora few minutes before coating onto the suitable support. The details ofsuch coating techniques are well known to those skilled in the art. Theforegoing procedure and proportions are to be regarded only asillustrative. Clearly, the invention is directed to any silver halideemulsion containing a supersensitizing combination of the invention,e.g., gelatinosilver chloride, -chlorobromide, -chloroiodide,-chlorobromoiodide, -bromoiodide, etc., emulsions. Fine grainphotographic emulsions, such as those described by Sutherns in US.patent application Ser. N0. 622,034, filed Mar. 10, 1967, can also besupersensitized in accordance with this invention.

The emulsions of this invention can contain the chemical sensitizers,speed increasing compounds, plasticizers, hardeners and coating aids,and the silver halide grains can be dispersed in any of the binders,that are described and referred to by Graham et al. in US Pat. 3,046,129issued July 24, 1962.

The following examples are included for a further understanding of theinvention.

EXAMPLES 1 TO 19 These examples illustrate the supersensitizationproduced with the compounds containing the pyrazole nucleus incombination with various methane dyes of the invention. The testingprocedure and the results thereof are set forth in the followingdescription and Table 3.

are) The specified cyanine dyes and heterocyclic compounds areidentifiable from Tables 1 and 2 above.

To different portions of the same batch of melted gelatino-silverbromoiodide emulsion, containing 0.77 mole percent iodide, of the typedescribed by Trivelli and Smith, Phot. Journal, 79, 330 (1939), areadded mg. per mole of silver of dye and the heterocyclic compounds inthe proportions given in Table 3 hereinafter. In each case, after beingdigested at about 50 C. for 10 minutes, the emulsion is coated at acoverage of 432 mg. silver per square foot on a cellulose acetate filmsupport. A sample of each coating is exposed on an Eastman IBSensitometer to light from a tungsten source modulated by a step-wedgeand Kodak Wratten No. 16 filter and processed for three minutes in KodakDeveloper D-l9 which has the following composition:

G. N-methyl-p-aminophenol sulfate 2.0 Hydroquinone 8.0 Sodium sulfite(desiccated) 90.0 Sodium carbonate (monohydrate) 52.5 Potassium bromide5.0

Water to make 1.0 liter.

' and then fixed in a conventional sodium thiosulfate fixing bath,washed and dried. Densitometric measurements are then made of thedeveloped images of each coating. The relative speed values aredetermined by the exposure necessary to produce a density of 0.3 abovefog, an arbitrary relative speed of 100 being chosen for the controlcontaining only dye. The results are listed in the following tabletogether with the values for gamma and fog.

TABLE 3.-SUPERSENSITIZATION BY PYRAZOLE TYPE 00 MP0 UN DS (Addendum) DyeN 0.. 80 mg. per Addendum .3 mole of to 10 gJmole Relative Example No.silver silver speed 7 Fog A 100 2. 40 06 A. 170 2. 74 06 A 182 2. 40 08B 100 1. 06 B 174 1. 99 06 A 100 2. 34 06 A 234 2. 72 08 A 112 2. 78 06A 214 2. 70 08 A 200 2. 70 08 B 100 2. 06 06 B 155 1. 96 09 B 151 1. 9006 B 151 2. 04 06 B 123 2. 02 06 B 347 2. 02 ()8 G 100 2. 54 06 G 27 4808 G 118 2. 78 06 H 100 2. 46 06 II 186 2. 40 08 II 269 2. 32 12 II 2632. 38 06 K 100 2. 60 07 K 141 2. 72 07 1g 148 2. 74 08 Ix 2. 90 08 E 1002. 46 06 E 214 2. 28 08 E 229 2. 22 06 E 339 2. 30 (JG 3 100 1. 96 06 C355 2. 50 07 J 100 2. 46 08 J 151 2. 44 08 F 100 2. 38 09 F 692 1. 58 11I 100 2. 52 08 I 309 2. 28 12 D 100 3. 10 08 D 204 2. 64 08 A 100 2. 6208 A 132 2. 20 07 A 214 2. 30 48 A 100 2. 96 07 A 138 2. 45 06 Z 100 1.28 05 A 100 1. 08 05 A 151 0. S4 04 S 100 1. 62 04 Y 407 0. 96 06 TABLE4 Concentration compound No. I (g./mle Relative Example N0. silver) spee7 Fog These data indicate that the optimum concentration of the addendumin the supersensitizing combinations of the invention are as previouslymentioned generally in the range of about 0.3 to 1.0 g./mole of silver.

EXAMPLES 20 TO 44 These examples illustrate the supersensitizationproduced with the tetrazoles and tetrazolium salts in combination withvarious methine dyes coming under the defini tions of Formulas :IV to VIabove. The testing procedure is exactly the same as that described inthe preceding examples and the results are tabulated in similar mannerin the following Table 5.

TABLE 5.SUPERSENSITIZATION BY TETRAZOLE TYPE COMPOUNDS [Addendum[Addendum and cone.

Dye No. and superseusl- Example cone. (g./ tizer (gJmole Relative No.mole silver) silver) speed 7 Fog 20(a) A (0.053) 100 3.22 .07 A (0.053)115 3. 06 06 P (0.05) 100 2.80 .08 P (0.05) 436 3.90 .33 P (0.038) 1003. 90 .07 P (0.038) 269 5. 40 06 P (0.030) 100 2.82 .08 P (0.030) 2514.15 .07 P (0.030) 148 3. 80 07 P (0.030) 355 3. 64 .07 D (0.03) 100 3.28 07 D (0.03) 380 3. 24 06 D (0.03) 427 4. 40 T (0.04) 100 3. 44 06 T(0.04) 191 3. 12 05 S (0.015) 100 2. 80 06 S (0.015) 257 3. 05 S (0.015)240 4. 60 06 U (0.015) 100 3. 04 08 U (0.015) 129 3. 60 05 R (0015) 1003.04 .08 R (0.015) 186 2. 74 07 A (0.06) 100 2.90 07 A (0.06) 138 2. 8007 L (0.08) 100 1. 06 L (0.08) 209 3. 06 M (0.08) 100 1. 30 .07 M (0.08)178 3. 10 07 B (0.05) 100 1. 07 B (0.05) 631 3. 16 06 Q (0.033) 100 2.50 05 Q (0033) 289 3. 26 06 X (0,04) 100 08 X (0.04) 1,200 3. 28 13 A(0.05) 100 2. 75 08 A(0.05) 141 2. 84 05 A (0.05) 151 2. 68 .07 O(0.115) 100 2. 16 06 C (0.115) 282 2. 98 06 O (0.115) 162 2.80 .05 B(0.080) 100 2.14 .07 B (0.080) 141 3.00 04 B (0.080) 151 2. 64 O (0.115)100 2. 57 06 TABLE 5.-Continued Addendum and cone.

Dye N o. and supersensi- Example cone. (g./ tizer (g./mole Relative Nomole silver) silver) speed 7 Fog O (0.115) 178 2. 44 04 O (0.115) 30!)3. 18 03 0 (0.115) 513 3. 26 03 O (0.115) 417 3. 30 03 O (0.115) 166 2.36 03 O (0.115) 219 2. 22 04 V (0.115) 100 3. 18 04 V (0.115) 155 3. 1403 W (0.115) 100 1. 70 04 W (0.115) 110 2. 30 04 W (0.115) 132 3.18 03 v0.1 100 2. 40 .03 V (0.1) 308 2. 70 03 C (0.12) 100 1. 47 03 C (0.12)501 2. 04 03 B (0.1) 100 1. 03 B (0.1) 468 2.00 03 C (0.12) 100 1. 74 04C (0.12) 347 2. 76 03 Y 0.070 100 Y 0.070) 290 It will be noted fromabove Table 5 that in each instance substantial improvement in relativespeed over each dye alone is shown by the supersensitizing combinationsof the invention.

EXAMPLES 45-57 These examples illustrate the supersensitization producedwith the triazoles and imidazole compounds of the invention incombination with various methine dyes coming under the definitions ofFormulas IV to VI above. The testing procedure is exactly the same asthat described in the preceding examples and the results are tabulatedin similar manner in the following Table 6.

TABLE 6.SUPERSENSITIZATION BY TRIAZOLE AND IMIDAZOLE TYPE COMPOUNDS{Addendum} Addendum Dye N 0. and and cone. Example cone. (g./ (g./m01eRelative N 0. mole silver) silver) speed '7 Fog Y 0.070 100 1. 32 00 Y0.070 XXVII 0 as 0, 170 1. 40 .00 Y 0.070 None 100 1. 50 00 Y 0.070)XXVIII 1.0 0, 400 1.68 00 Y 0.070 XXIX 0.00 000 1. 33 .05 z 0.000 1001.20 .05 2 0.000 XXXVI 0 a 101 1.18 .12 D 0.05% None 100 0. .04 D 0.053xfg vn 430 1.10 .00 0. 05 None; 1.50 .04 0. 05 XXX 0 00)-- 1. 24 .04 (0.04 None 100 1. 34 .05 0. 04 102 1. 15 .05

1 0.04 XX'Xvi 0.3 138 1.02 .14 1 0.04 XXv 186 0. 70 .05 1 0.01 XEgIVII173 1.10 .05 Y 0.070) None 100 1.70 .00 Y 0. 070 5,750 1. 59 .00 Y 0.070X%(()'X)VII 55,000 1.50 .05

.0 w 0. 070 None 100 1. 55 .04 w 0. 070 xggi vrr 132 1.40 .05 A 0.000100 1. 0s .05 A 0.000 XXXVI 0 a 151 0.88 .25 Y 0. 070 None 100 0. 00 .04Y 0. 070 10251 3111 1,380 1.48 .04 Y (0. 070 XX'XI'I 0.3 750 1.18 .04 Y0. 070) XXXI 0.3 031 1. 74 .04 Y (0.076) None 100 1.00 .04 Y 0. 07010251 7111 2, 240 1.18 .04. Y 0. 070) 5,510 1.24. .04

Referring to above Table 6, it will be observed that the relative speedfor each of the specified supersensitizing combinations is markedlygreater than that of the control 1 1 example containing the dye alone,i.e., without the supersensitizing addendum. Remarkably high relativespeeds are shown for Example 46 (c) comprising Dye No. Y and addendumCompound No. XXIX, and Example 51(c) comprising Dye No. Y and addendumCompound No. XXXVII, with no increase in fog in each instance.

It will be apparent from all of the foregoing description that stillother combinations of the invention can be produced by appropriateselection of other heterocyclic compounds of the type described hereinwith other photographic methine dyes and that such combinations likewisewill result in supersensitized photographic silver halide emulsions.

The invention has been described in detail with particular reference topreferred embodiments thereof, but, it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention described hereinabove and in the appended claims.

I claim:

1. A photographic silver halide emulsion containing a supersensitizingcombination of (1) a heterocyclic compound having the following formula:

wherein R and R each represents a member selected from the groupconsisting of a hydrogen atom or an aryl group; and, R represents amember selected from the group consisting of hydrogen and amino; and (2)a photographic spectral sensitizing methine dye selected from thosehaving one of the following formulas:

wherein n and e each represents a positive integer of from 1 to 2; d andIn each represents a positive integer of from 1 to 3; R and R eachrepresents a member selected from the group consisting of an alkyl groupand an aryl group; X represents an acid anion; Z and Z each representsthe non-metallic atoms necessary to complete a nucleus selected from thegroup consisting of a thiazole nucleus, an oxazole nucleus, a selenazolenucleus, a thiazoline nucleus, a pyridine nucleus, a3,3-dialkyl-indolenine nucleus, a quinoline nucleus and an imidazolenucleus; L repre- 12 sents a methine linkage; and, Q represents thenon-metallic atoms necessary to complete a heterocyclic ketomethylenenucleus selected from the group consisting of a 2-pyrazolin-S-onenucleus, an isoxazolone nucleus, an oxindole nucleus, a 2,4,6triketohexahydropyrimidine nucleus, 21 rhodanine nucleus, a2(3H)-imidazo[1,2-a]pyridone nucleus, a 5,7dioxo-6,7-dihydro-5-thiazolo[3,2-a]pyrimidine nucleus, a 2thio-2,4-oxazolidinedione nucleus, at thianaphthenone nucleus, a 2thio-2,5-thiazolidinedione nucleus, a 2,4-thiazolidinedione nucleus, athiazolidinone nucleus, a 2-thiaZolin-4-one nucleus, a2-imino-4-oxazolidinone nucleus, a 2,4-imidazolidinedione nucleus, a2-thio- 2,4-imidazolidinedione nucleus, and a 2-irnidazolin-5-onenucleus.

2. A photographic silver halide emulsion comprising a supersensitizingcombination of (l) a heterocyclic compound selected from the groupconsisting of 3 -amino-5-phenyl-1,2,4-triazole,

3,3 -bis( 1,5 -diphenyl- 1 ,2,4-triazole 1,5 -diphenyl- 1 ,2,4-triazole,

4-amino-3,5-di-(p-aminophenyl)-1,2,4-triazole,

po1y(1,2,4-triazole),

4- S-cyanomethyll-phenyl- 1 ,2,4-triazol-3-ylbenzaldehyde-N-chlorophenylhydrazone,

3,3 '-p-phenylenebis-(S-cyanomethyl-l-phenyl-1,2,4-

triazole and (2) a methine dye selected from the group consisting of3,3-di-fl-hydroxyethylthiadicarbocyanine salt and 5-[di- (1ethyl-2(1H-p-naphthothiazolylidene)isopropylidene]-1,3-di({R-methoxyethyl)-barbituric acid.

3. A photographic silver halide emulsion comprising a supersensitizingcombination of (1) the heterocyclic compound 1,5-diphenyl-1,2,4-triazoleand 2) the methine dye 5-[di(l-ethyl-2(1H) ,8naphthothiazolylidene)isopropylidene]-1,3-di-fl-rnethoxyethyl)-barbituricacid.

4. A photographic element comprising a support having a coating thereoncontaining an emulsion of claim 1.

5. A photographic element comprising a support having a coating thereoncontaining an emulsion of claim 2.

6. A photographic element comprising a support having a coating thereoncontaining an emulsion of claim 3.

References Cited UNITED STATES PATENTS 2,271,623 2/1942 Carroll 961042,566,167 8/1951 Carroll et a1 96104 2,680,686 6/1954 Van Dormael 96l043,255,012 6/1966 Glockner et al 9674 3,397,987 8/1968 Luckey et al.96-l09 3,411,915 11/1968 Jones et al. 96104 3,420,664 1/1969 Dersch etal. 96109 3,457,078 7/1969 Riester 96-104 3,468,665 9/1969 Misu et al96-74 I. TRAVIS BROWN, Primary Examiner U.S. Cl. X.R. 96109

